In 1978, Bp. Timothy was appointed to succeed Bp. Iakovos (Garmatis) as Bishop of the Seventh District of Detroit in the United States of America. In 1979 after the re-designation of districts as diocese, he was enthroned as Bishop of the Diocese of Detroit. In 1995, Bp. Timothy retired to Greece.

On December 11, 1998, Bp. Timothy died in an Athens hospital following complications from asthma. He was buried on December 15, 1998 in Kaisieriani Cemetery after a funeral service at the Kimisis Tis Theootokou Church in Kaiseriani, Athens.